Manufacture of tubular structures



y 2 .Sheets-Sheet l Jan. 29, 1946.4 P. R. GOLDMAN MAUFACTURE OF 'VIUBULAR STRUCTURES Original Filed Aug. '7

Jan. 29, 19.46. P. R. GOLDMAN MANUFACTURE OF: TBULAR STRUCTURES original Filed Aug. 7-, 1942 v 2 Sheets-Sheet 2 Tn/ve 2".' I Pall/Z R. odzuan arced relation as seen in Fig. 1. The angleV of inclination of the end cuts 4l, and the lengthY Vof the sections 31, may be variously selected as appropriate for the particular radius of curvature desiredfor the Vstructure as a'whole; Such trun- Y Y cate orY segmental sectionsY 31 mayv be directly abutted; and preferably bonded, end to end, or.

they may be assembled with intervening cross walls 38. They may be left hollow or they may Y be lled with and serve as covering forvbalsa or tubular structures of the parent application. The curved tubular casing 36 may be formed in arcuate sections of any desired length, into which the tubular elements 31 are inserted, or such casing may be formed by winding the veneeringor other strip material about thev assembled sectional elements 31 and their end walls or spacers 38 where the latter are employed. y As previously stated, the method of the invention including the steps of angularly severing a length of straight lamellar Vveneer tubing into relatively short truncate sections and rearranging them to provide liner or chamber-dening means within a tubular casing, is applicable to instances where the tubular device or casing is completed through 360 of arc, to full circular form, as in Fig. 1, and also to structures of less than 360 arcuate extent. Any segmental or arcuate length ,of the outer tubular casing may be employed, as

for example, in the formation of angular unions and connections between other tubing elements, as Adisclosed in the parent application.

Fig. 4 herein illustrates one such less than 360 arcuate structure, wherein the tubular casing'46 as a whole comprises substantially semicircularv sections or end formations united by straight lengths 46', 46' to provide the main buoyant supporting frame or float for a raft or the like. The method of forming and assembling the Yliner or chamber-dening elements 31 for such semi-,circular or other arcuate lengths, with or without cross-members or ,chamber end walls 38, has already been described with referenceto Y other ller material, similarly as for the straight l YitY ation withthe inner cross walls or for providing lapped'joints for adjoining lengths or ends of 'the casing. Y

My invention is not limited to the particular steps for the practice thereof asherein illustrated or described, its Vscope being pointed out in the following claims. I claim: V1. In the formation method which comprises winding plies of wood veneer Aabout a straight longitudinal axis and bonding them together so as to form a tube of indeterminate length, severing the tube transversely` along alternatelyv oppositely inclined planes to provide a plurality of relatively short f lengths. of tubing, rearranging the severed lengths endwiser in longitudinal series in angular axial Y interrelatiomforming a curvilinear tubular cas- Figs. 1 to 3. It is again noted that the angle I of inclination for the end cuts 41, and the length of thesections 31 between such cuts is calculated in accordance with the radius of curvature for the particular arcuate tubular casing with which they are to be employed. In general, the less the curvature, the nearer the plane of severance be-` tween sections 31 approaches a plane perpendicular to their axis. l Y

It will also be understood,ras in the parent application, that at the ends of the casing ele-1 ments such as 36 and 46 which enclose the sec-` tionalized truncate members constructed and arranged in the manner described, the several layers or plies of the casing may be terminated indifferent transverse planes, for seating coopering by winding veneer. stripping, interposing cross-walls between adjacent rearranged relatively short tubing lengths thereby to intercon- V nect and provide end closures Vfor the same, and disposing such lengths in the wound curvilinear casing. f

2. That method of forming arcuate tubular structures having sectionalized innerV liner or chamber-dening elements, which comprises winding a plurality of plies of Wood veneer about a common axis and bonding them together toV provide a straight tube, severing such straight tube transversely along alternately oppositely inclined planesrspaced and inclined in proportion to the degree of curvature of the arcuate tubular structure to be formed, disposing the severed tube portions with their axes respectively perpendicular to selected angularly spaced radii of curvature'so asV to conform their respective axes substantially to the selected line of curvature, inserting end wall elements between said tube portions to form individual cells, and enclosing them in an arcuate tubular casing of the selected degree of curvature' and ofV an internal diameter equivalent to the major cross dimension of the respective enclosed tube portions measured in the veneer compartmental tubing which comprises the steps of winding and interbonding a plurality of plies of veneer into a straight tubular element, Y

severing such element along equi-spaced alternately oppositely like inclined transverse planes to form a series of similar truncate tubular sections, inverting alternate sections, realigning such sections with their axes respectively perpendicular to selected angularly spaced radii of curvature so as to be generally confromant tothe line of curvature desired for4 the tubing, installing and securing transverse wall elements between said sections to provide a series ofV closed chambers, and enclosing the whole in a lamellar veneer casing.

PAUL R. GOLDMAN.

vofV tubular structures, the Y 

